<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			.z1, .z2, .z3 {
				position: absolute;
				text-align: center;
				width: 200px;
				height: 200px;
			}
			.z1 {
				z-index: 1;
				background: red;
			}
			.z2 {
				z-index: 2;
				top: 40px;
				left: 40px;
				background: blue;
			}
			.z3 {
				z-index: 3;
				top: 80px;
				left: 80px;
				background: yellow;
			}
		</style>
	</head>
	<div class="z1">z-index:1</div>
	<div class="z2">z-index:2</div>
	<div class="z3">z-index:3</div>
	<body>
	</body>
</html>
